The present invention relates generally to a method and an apparatus for recognizing images, and a copying machine and a printer using the same.
In a reading portion in a general digital color copying machine (laser type), as shown in FIG. 1, an image sensor 1 formed by a line of CCDs having a reading width identical to the width of an original 2 is used and provided opposing the original. In this example, the width d of image sensor 1 in practice is smaller than the width D of the original, since a reducing optics including a lens 3 is used, but in some other cases, the same width is employed. If the lengthwise direction of image sensor 1 is set as a main scanning direction, image sensor 1 may be moved back and forth in a sub scanning direction orthogonal to the main scanning direction.
In reading an original using such image sensor 1, the entire raster scan method is employed. More specifically, as shown in FIG. 2, image sensor 1 is positioned at the top of original 2, and the first line a (in the main scanning direction) is read by image sensor 1. Then, image sensor 1 is moved by 1 line in the sub scanning direction, and the next line b (in the main scanning direction) is read. Thereafter, the process is sequentially repeated to read the entire original, based on which a prescribed image processing is performed for printing.
The copying machine employing the kind of entire raster scanning method as described above is capable of copying data in very high precision, and therefore a printed, out copy could be almost identical to the original. The machine could be therefore used to counterfeit anything prohibited to copy such as paper currencies.
Hence, in order to prevent such misconduct, an image recognizing apparatus to recognize particular kinds of originals is installed and image data read by image sensor 1 is subjected to a recognizing process, so that the presence/absence of a particular pattern printed on any items, i.e., a pattern prohibited to copy, is determined. If the particular pattern is detected, output is stopped, or a prescribed prohibiting process such as painting out is performed.
Meanwhile, there are other color copying machines than the digital color-copying machine such as ink jet type machine. The method of reading images by this type of copying machine is as shown in FIGS. 3A and 3B. More specifically, an image sensor 5 of a small width is provided opposite to original 2. Image sensor 5 is capable of reading 128 dots at 400 dpi. There are further provided an X motor for moving image sensor 1 in the X-direction and a Y motor for movement in the Y-direction, and revolution of each of the motors is controlled to move image sensor 5 to an arbitrary position in a two-dimensional plane of original 2.
In reading image data, the X motor is normally rotated to move image sensor 5 in the X-direction, from position X0 to position of Xn. During the movement, image data at an opposing portion (a reading region a in the first line) is read. Then, the X motor is reversely rotated, and the Y motor is rotated by a prescribed angle in the normal direction to move image sensor 5 obliquely as shown in broken line in the figure, and positioned at the head (X0) of reading region b in the second line. Then, the Y motor is stopped, and the X motor is normally rotated to move image sensor 5 from position X0 to position Xn in reading region b in the second line. During the movement, image data in the opposite portion (region b) is read.
Thereafter, by repeating the above process, the entire original is read. Reading of images on the basis of each region a, b . . . is by raster scanning in a stripped shaped region as shown in FIG. 4. (The solid line arrows in the figure denote periods of reading images, and the line connecting the adjacent arrows represents the image sensor in the process of moving, and data of each pixel is read following the arrows.)
In printing out, each time one region is read, an image corresponding to the region is formed by a prescribed image processing, and the thus formed image for the one region is output. More specifically, as shown in FIG. 5, reading data for one region (region a in the first line in the shown example) is applied from the reading portion including image sensor 5 to image processing portion 6, where a prescribed image processing is performed, data for one region is applied to the output portion, and data corresponding to a region axe2x80x2 for the read region a is printed using a printing head 7 (equal size printing). Thus, image reading and image formation are linked to print data bit by bit, so that an inexpensive, small memory copying machine may be implemented.
Furthermore, printing head 7 provided at the output portion has 128 nozzles for one color component corresponding to the reading portion, and the on/off of the color component for the corresponding nozzles is controlled based on the color of each pixel detected by the detection element of a corresponding sensor.
The above ink jet type color copying machine is not provided with an image recognizing apparatus such as those installed in a conventional laser type digital color copying machine for recognizing special kinds of originals.
However, in recent years, the above-described ink jet type color printer came to be capable of highly precise color printing, and therefore the sameness between an original and a copy thereof is increased. Thus, there is a need for an image recognizing apparatus for recognizing particular kinds of originals. As described, however, the image recognizing apparatus that has been used in the entire raster scanning digital color copying machine cannot be applied as is, because of the difference in the scanning method.
Furthermore, since the operation of the reading portion in the process of expansion/reduction is different between these copying machines, the above-described problem is more notable. More specifically, in the digital color-copying machine, as shown in FIGS. 1 and 2, image sensor 1 moves only in a single direction. As a result, the resolution in reading an original in the width-wise direction (in the arranging direction of image sensor 1/the main scanning direction) is constant regardless of the expansion/reduction ratio. The resolution in reading in the sub scanning direction is changed by expansion/reduction. More specifically, the moving speed of image sensor 1 in the sub scanning direction is lowered in the expansion process, and raised in the reduction process, and the speed is adjusted by the expansion/reduction ratio. Such simple movement allows image data with the same resolution to be available regardless of the magnification simply by thinning and supplementing image data read in the sub scanning direction as necessary.
In contrast, in the ink jet type machine, 128 nozzles provided at printing head 7 are controlled at a time for output, during reading a strip-shaped region, data from the head to N-th data is used, while N+1-th data and on is not used, and the Y motor is rotated to move image sensor 1 for a distance corresponding to the N pieces of data in the image sensor, in order to read the next strip-shaped region (the specific process of which will be described later).
Therefore, part of an output signal from image sensor 1 is invalidated, the moving distance in the Y-direction is not constant, unlike the reading mechanism of the conventional digital color copying machine, and the conventional recognizing apparatus as is cannot be applied.
Furthermore, in the sub scanning direction, the moving speed of the image sensor is changed depending upon the magnification, as is the case with the laser type apparatus. Accordingly, read data is two-dimensionally changed depending upon the magnification, and the same image data is not available depending upon the magnification, simply by thinning or supplementing the read data in the order of application.
The present invention is in view of the above-described background, and it is an object of the present invention to provide a method and an apparatus which can be used even in a copying machine and a printer such as an inkjet type machine which reads (externally receives) data in a strip-shaped region smaller than the entire original, and produces printing data based on applied image data for output, and to provide a copying machine and a printer employing such method and apparatus which permit data including particular data (particular patterns) to be surely detected.
Another object of the present invention is to provide a method and an apparatus permitting zooming process in addition to the above object of the invention.
In order to achieve the above-described objects, an image recognizing apparatus according to the present invention including an image processing portion which produces printing data based on input image data for output to an output portion includes a recognizing apparatus which recognizes particular images.
Image data input to the image processing portion is sequentially input in the form of a number of strip-shaped small regions formed by dividing the entire image by scanning the entire image. The output portion sequentially outputs image data as a prescribed number of lines of strip-shaped data based on the output of the image processing portion, the recognizing apparatus detects particular images from an amount of said image data produced by a plurality of scanning operations, compares the data with internally stored data and applies the result to said output portion.
The entire image is divided into small regions and input to the image processing portion, where the recognizing apparatus detects if the input image data is any of particular images. As a result, a particular document may be detected without providing an image memory for 1 page to read the entire image.
According to another aspect of the invention, in the image recognizing apparatus, the image processing system is provided with an image reading portion (reading portion 10) which reads an image on the basis of a strip-shaped small region (each region extending in the sub scanning direction) for the entire image reading region, and image processing unit (image processing portion 20) which produces printing data based on image data output from the image reading portion for output. In further detail, the image processing system to which the present invention portion for output. In further detail, the image processing system to which the present invention is applied has a zooming function, and the zooming process operates to satisfy the following requirements (1) to (3).
(1) The substantial reading width of said strip-shaped small region is changed depending upon the magnification.
(2) The widths of printing data available by expansion are equal regardless of the magnification (constant 128 dots in the embodiment).
(3) The width of printing data available by reduction is equal regardless of the magnification (constant 64 dots in the embodiment).
The image recognizing apparatus in the image processing system which recognizes a particular image in said read image data (xe2x80x9cparticular mark M, particular patternxe2x80x9d in the embodiment) performs a prescribed recognizing processing based on image data after zooming operation produced in said image processing unit, on the basis of a strip-shaped small region less than one original page, and recognizes said particular image, and includes recognizing unit for recognizing said particular image and output unit for outputting the result of recognition by said recognizing unit. Note that in this embodiment, the recognizing unit and output unit are collectively referred to as recognizing apparatus 50, 50xe2x80x2 or 50xe2x80x3.
The image processing system to which the present invention is applied is not limited to the above, and the invention is applicable to any system which receives data from an external apparatus, and includes image processing unit for producing printing data based on the received image data for output, and the zooming processing by said image processing system may be the process satisfying the following requirements (1) to (3).
(1) The substantial reading width of said strip-shaped small region is changed depending upon the magnification.
(2) The widths of printing data available by expansion are equal regardless of the magnification.
(3) The widths of printing data available by reduction are equal regardless of the magnification.
Note that the zooming process is not essential in the above image processing system, and the above elements may be arbitrarily combined. Various combinations of the above elements are given in the following embodiments.
Preferably, said printing data is binary data representing whether or not to output ink corresponding to each color component, and said recognizing unit performs a recognizing processing based on multi-value image data produced in said image processing unit after zooming operation and before producing said binary data. The image data used for said recognizing process may be a signal that specifies a color component other than optical color information such as YMC data and YMCK data.
Meanwhile, in the image recognizing method according to the present invention, an image is read on the basis of a plurality of parallel strip-shaped small regions for the entire image reading region, and printing data is produced based on the resulting image data for output. If said printing data is produced by zooming process, the following requirements (1) to (3) are satisfied.
(1) The substantial reading width of said strip-shaped small region is changed depending upon the magnification.
(2) The widths of printing data available by expansion are made equal regardless of the magnification.
(3) The widths of printing data available by reduction are made equal regardless of the magnification.
A prescribed recognizing processing is performed based on image data after zooming operation, on the basis of a strip-shaped small region less than one original page, and a particular image included in said image data is recognized.
As an alternative solution, image data is received from an external device on the basis of a plurality of parallel strip-shaped small regions for an image region to be printed out. Then, printing data is basically produced and output based on the received image data. If the zooming processing is performed to produce said printing data, the following requirements (1) to (3) are satisfied.
(1) The substantial reading width of said strip-shaped small region is changed depending upon the magnification.
(2) The widths of printing data available by expansion are made equal regardless of the magnification.
(3) The widths of printing data available by reduction are made equal regardless of the magnification.
A prescribed recognizing processing is performed based on image data after the zooming processing, on the basis of a strip-shaped small region less than one original page, and a particular image included in said image data is recognized.
More preferably, said printing data is binary data representing whether or not to output ink corresponding to each color component produced in said image processing unit after zooming processing, and a prescribed recognizing processing is performed based on multi-value image data before producing said binary data, in order to recognize said particular image. Said recognizing processing may be performed based on image data of signals that specify a color component other than optical color information (RGB data) such as YMC data and YMCK data.
According to the present invention, in a copying machine which performs a zooming processing to image data applied on the basis of a strip-shaped small region, produces printing data, and performs a printing processing based on the printing data on the basis of a strip-shaped small region, there is provided an image recognizing apparatus for recognizing a particular image on the basis of a strip-shaped small region less than one original page, using the data after the zooming processing, and outputting is prohibited if the particular image is recognized by the recognizing apparatus.
Also according to the present invention, in a printer which performs a zooming processing to image data applied on the basis of a strip-shaped small region, produces printing data, and performs a printing processing on the basis of a strip-shaped small region based on the produced printing data, there is provided an image recognizing apparatus for recognizing a particular image, using the data after the zooming operation, and outputting is prohibited, if the particular images recognized by the recognizing apparatus.
In summary, according to the present invention, the recognizing processing is based on data without zooming processing or after zooming operation. More specifically, in an ink jet type copying machine or printer, unlike a laser type printer, printing data is produced for each image data available from a small region specified by main scanning and sub scanning operations, and printing processing is performed. In the zooming processing, the substantial reading width varies depending upon the magnification. (In the embodiment, image data read by the reading portion is 128-dot data similarly to the case of equal size printing, but the substantial reading width is reduced, because image data for dots beyond N dots from the head is not used.) Thus, on the side of the read image data, data changes depending upon the magnification, the width of data after zooming processing is specified into two kinds, the case of reduction and the case of expansion.
As a result, corresponding operations are alleviated. By obtaining information as to whether the zooming processing is for expansion or reduction, the algorithm is switched between prepared recognizing algorithms for prescribed processing. Since prescribed recognizing processing is performed to image data after a zooming operation, the same apparatus may be used for a printer that does not have a reading portion.
Terms used herein will be now defined.
In the specification, as shown in FIG. 6, the scanning direction A of sensor 5 itself is specified as a main scanning direction, and the direction B in which the sensor moves for reading a strip-shaped region is specified as a sub scanning direction. Thus, the sensor is moved in the sub scanning direction while reading an image in the main scanning direction and image data in a strip-shaped region is read as raster-scanned. Furthermore, the movement of the sensor in synchronization with the printing head, in other words the movement C of the printing head for reading the next strip-shaped region is specified as page-scanning.
The zooming processing includes expansion and reduction processing. The zooming operation includes not only such expansion/reduction processing but also equal-size processing wherein the magnification is 100%, or processing without zooming processing.
The output prohibiting processing includes not only stopping outputting, but also painting in solid black all over or outputting anything different from the original such as the case of printing a special design over the original image.